Renal medullary carcinoma
Encyclopedia
Renal medullary carcinoma is a rare type of cancer
that affects the kidney
. It tends to be aggressive, difficult to treat, and is often metastatic at the time of diagnosis. Most individuals with this type of cancer have sickle cell trait
or rarely sickle cell disease, suggesting that the sickle cell trait may be a risk factor for this type of cancer.
or occasionally in those with sickle cell disease.
Other researchers have reported a palpable renal mass or enlarged lymph nodes.
, in which the person carries one normal copy of the hemoglobin A
gene (HbA) and one copy of the hemoglobin A gene harboring the genetic mutation found in sickle cell disease (HbS). These individuals do not have sickle cell disease but can manifest symptoms such as kidney damage
over the course of their lives. The other genetic or environmental factors that contribute to the risk of renal medullary carcinoma are unknown.
(usually abdominal/pelvic CT scan
) studies and ultimately surgical biopsy
and pathological examination
of the tumor. Findings on radiographic examination are non-specific and can reveal a mass deep within the kidney. Histopathology
studies show a distinctive pattern that can be distinguished from other renal tumors.
, presents at an advanced stage when the cancer has already metastasized, and is resistant to chemotherapy
. It therefore poses a significant management challenge. Current treatment options include surgical resection
and chemotherapy with a variety of agents, including (but not limited to) ifosfamide
, etoposide
, carboplatin
, and topotecan
. A recent study looked at the use of methotrexate
, vinblastine
, doxorubicin
, and cisplatin
in 3 patients and saw a partial response and longer survival than historical reports.
, the most common renal tumor of childhood, is responsible for 6-7% of childhood cancer whereas all remaining primary renal tumors (among which is included renal medullary carcinoma) collectively account for less than 1% of all childhood cancer and less than 10% of primary kidney tumors in childhood.
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
that affects the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
. It tends to be aggressive, difficult to treat, and is often metastatic at the time of diagnosis. Most individuals with this type of cancer have sickle cell trait
Sickle cell trait
Sickle cell trait describes a condition in which a person has one abnormal allele of the hemoglobin beta gene , but does not display the severe symptoms of sickle cell disease that occur in a person who has two copies of that allele...
or rarely sickle cell disease, suggesting that the sickle cell trait may be a risk factor for this type of cancer.
Classification
Renal medullary carcinoma has been termed "the seventh sickle cell nephropathy" because it is found almost exclusively in individuals with sickle cell traitSickle cell trait
Sickle cell trait describes a condition in which a person has one abnormal allele of the hemoglobin beta gene , but does not display the severe symptoms of sickle cell disease that occur in a person who has two copies of that allele...
or occasionally in those with sickle cell disease.
Medical signs and symptoms
In a case series of 34 patients, Davis and colleagues reported the following signs and symptoms:- macroscopically visible (gross) hematuriaHematuriaIn medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
(60%) - abdominal or back/flank pain (50%)
- significant weight loss (25%)
Other researchers have reported a palpable renal mass or enlarged lymph nodes.
Causes/genetics
The etiology of renal medullary carcinoma is still not completely understood. However, the majority of individuals diagnosed with this type of cancer have had sickle cell traitSickle cell trait
Sickle cell trait describes a condition in which a person has one abnormal allele of the hemoglobin beta gene , but does not display the severe symptoms of sickle cell disease that occur in a person who has two copies of that allele...
, in which the person carries one normal copy of the hemoglobin A
Hemoglobin A
Hemoglobin A or adult hemoglobin is the most common human hemoglobin tetramer, comprising over 97% of the total red cell hemoglobin. It consists of two alpha chains and two beta chains ....
gene (HbA) and one copy of the hemoglobin A gene harboring the genetic mutation found in sickle cell disease (HbS). These individuals do not have sickle cell disease but can manifest symptoms such as kidney damage
Nephropathy
Nephropathy refers to damage to or disease of the kidney. An older term for this is nephrosis.-Causes:Causes of nephropathy include administration of analgesics, xanthine oxidase deficiency, and long-term exposure to lead or its salts...
over the course of their lives. The other genetic or environmental factors that contribute to the risk of renal medullary carcinoma are unknown.
Mechanism
The finding that virtually all people affected by renal medullary carcinoma carry at least one copy of the HbS mutation suggests that sickle cell trait somehow predisposes to this type of cancer. The precise mechanism is unknown, however red blood cells with a sickle cell configuration have been identified in pathology specimens.Diagnosis
The diagnosis of renal medullary carcinoma is typically made after individuals with sickle cell trait present with the typical signs and symptoms outlined above, in combination with radiographic imagingRadiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
(usually abdominal/pelvic CT scan
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
) studies and ultimately surgical biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
and pathological examination
Pathology
Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
of the tumor. Findings on radiographic examination are non-specific and can reveal a mass deep within the kidney. Histopathology
Histopathology
Histopathology refers to the microscopic examination of tissue in order to study the manifestations of disease...
studies show a distinctive pattern that can be distinguished from other renal tumors.
Prevention
Renal medullary carcinoma is extremely rare and it is not currently possible to predict those individuals with sickle cell trait who will eventually develop this cancer. It is hoped that early detection could result in better outcomes but screening is not feasible.Management
This cancer is typically aggressiveMalignant
Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...
, presents at an advanced stage when the cancer has already metastasized, and is resistant to chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
. It therefore poses a significant management challenge. Current treatment options include surgical resection
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
and chemotherapy with a variety of agents, including (but not limited to) ifosfamide
Ifosfamide
Ifosfamide is a nitrogen mustard alkylating agent used in the treatment of cancer.It is sometimes abbreviated "IFO".-Uses:It is given as a treatment for a variety of cancers, including:...
, etoposide
Etoposide
Etoposide phosphate is an anti-cancer agent. It is known in the laboratory as a topoisomerase poison. Etoposide is often incorrectly referred to as a topoisomerase inhibitor in order to avoid using the term "poison" in a clinical setting...
, carboplatin
Carboplatin
Carboplatin, or cis-Diammineplatinum is a chemotherapy drug used against some forms of cancer...
, and topotecan
Topotecan
Topotecan hydrochloride is a chemotherapy agent that is a topoisomerase I inhibitor. It is the water-soluble derivative of camptothecin...
. A recent study looked at the use of methotrexate
Methotrexate
Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...
, vinblastine
Vinblastine
Vinblastine is an antimicrotubule drug used to treat certain kinds of cancer, including Hodgkin's lymphoma, non-small cell lung cancer, breast cancer, head and neck cancer, and testicular cancer. It is also used to treat Langerhan cell histiocytosis....
, doxorubicin
Doxorubicin
Doxorubicin INN is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA....
, and cisplatin
Cisplatin
Cisplatin, cisplatinum, or cis-diamminedichloroplatinum is a chemotherapy drug. It is used to treat various types of cancers, including sarcomas, some carcinomas , lymphomas, and germ cell tumors...
in 3 patients and saw a partial response and longer survival than historical reports.
Prognosis
Since the cancer most often presents at an advanced stage, prognosis is generally very poor, with median survival times of 3 months (range 1–7 months). Longer survival of beyond one year was reported in one patient and of up to eight years in one individual whose tumor was well circumscribed and non-metastatic at the time of diagnosis, suggesting that early detection could dramatically improve survival.Epidemiology
As of 2009, there have been approximately 120 reported cases of renal medullary carcinoma. In every instance except for one, the patients were positive for cell sickling. Wilms' tumorWilms' tumor
Wilms' tumor or nephroblastoma is cancer of the kidneys that typically occurs in children, rarely in adults.Its common name is an eponym, referring to Dr. Max Wilms, the German surgeon who first described this kind of tumor....
, the most common renal tumor of childhood, is responsible for 6-7% of childhood cancer whereas all remaining primary renal tumors (among which is included renal medullary carcinoma) collectively account for less than 1% of all childhood cancer and less than 10% of primary kidney tumors in childhood.